Spiral timepiece spring

Patent metadata

Field	Value
Publication number	US-10795317-B2
Application number	US-201816012274-A
Country	US
Kind code	B2
Filing date	Jun 19, 2018
Priority date	Jun 26, 2017
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

A spiral timepiece spring with a two-phase structure, made of a niobium and titanium alloy, and method for manufacturing this spring, including producing a binary alloy containing niobium and titanium, with niobium: the remainder to 100%; titanium between 45.0% and 48.0% by mass of the total, traces of components among O, H, C, Fe, Ta, N, Ni, Si, Cu, Al, of between 0 and 1600 ppm by mass of the total individually, and less than 0.3% by mass combined; applying deformations alternated with heat treatments until a two-phase microstructure is obtained including a solid solution of niobium with β-phase titanium and a solid solution of niobium with α-phase titanium, the α-phase titanium content being greater than 10% by volume, with an elastic limit higher than 1000 MPa, and a modulus of elasticity higher than 60 GPa and less than 80 GPa; wire drawing to obtain wire able to be calendered; calendering or winding.

First claim

What is claimed is:

1. A spiral spring with a two-phase structure, wherein the material of said spiral spring is a binary alloy comprising niobium and titanium, and which comprises:
niobium: the remainder to 100%;
a proportion by mass of titanium greater than or equal to 45.0 of the total and less than or equal to 48.0% of the total;
traces of other components among O, H, C, Fe, Ta, N, Ni, Si, Cu, Al, each of said trace components being comprised between 0 and 1600 ppm of the total by mass, and the sum of said traces being less than or equal to 0.3% by mass.

2. The spiral spring according to claim 1 , wherein the total proportion by mass of titanium and niobium is comprised between 99.7% and 100% of the total.

3. The spiral spring according to claim 1 , wherein the proportion by mass of titanium is greater than or equal to 46.0/%.

4. A spiral spring with a two-phase structure, wherein the material of said spiral spring is a binary alloy comprising niobium and titanium, and which comprises:
niobium: the remainder to 100%;
a proportion by mass of titanium greater than or equal to 40.0% of the total and less than or equal to 60.0% of the total;
traces of other components among O, H, C, Fe, Ta, N, Ni, Si, Cu, Al, each of said trace components being comprised between 0 and 1600 ppm of the total by mass, and the sum of said traces being less than or equal to 0.3% by mass,
wherein said spiral spring has a two-phase microstructure comprising a solid solution of niobium with β-phase titanium and a solid solution of niobium with α-phase titanium, the α-phase titanium content being greater than 10% by volume.

5. The spiral spring according to claim 1 , wherein the proportion by mass of titanium is greater than or equal to 46.5% and less than or equal to 48.0% of the total.

6. The spiral spring according to claim 1 , wherein the proportion by mass of titanium is less than or equal to 47.5% of the total.

7. The spiral spring according to claim 1 , wherein said spiral spring is a mainspring.

8. The spiral spring according to claim 1 , wherein said spiral spring is a balance spring.

9. The spiral spring according to claim 4 , wherein the proportion by mass of titanium is greater than or equal to 45.0% and less than or equal to 48.0% of the total.

10. The spiral spring according to claim 4 , wherein the proportion by mass of titanium is greater than or equal to 46.0%.

11. The spiral spring according to claim 4 , wherein the proportion by mass of titanium is greater than or equal to 46.5° % and less than or equal to 48.0% of the total.

12. The spiral spring according to claim 4 , wherein the proportion by mass of titanium is less than or equal to 47.5% of the total.

13. A method for manufacturing a spiral timepiece spring, comprising, in the following order:
producing a blank from a binary alloy comprising niobium and titanium, and which comprises:
niobium: the remainder to 100%;
a proportion by mass of titanium greater than or equal to 45.0% of the total and less than or equal to 48.0% of the total,
traces of other components among O, H, C, Fe, Ta, N, Ni, Si, Cu, Al, each of said trace components being comprised between 0 and 1600 ppm by mass of the total, and the sum of said traces being less than or equal to 0.3% by mass;

performing a treatment cycle including a prior beta-quenching treatment to a given diameter, such that the entire structure of the alloy is beta, then a succession of the pairs of deformation/precipitation heat treatment sequences, comprising the application of deformations alternating with heat treatments until a two-phase microstructure is obtained comprising a solid solution of niobium with β-phase titanium and a solid solution of niobium with α-phase titanium, the α-phase titanium content being greater than or equal 10% by volume, with an elastic limit higher than or equal to 1000 MPa, and a modulus of elasticity higher than 60 GPa and less than or equal to 80 GPa;
wire drawing to obtain a wire of round cross-section, and rectangular profile unformed rolling compatible with the entry cross-section of a calender roller press or of a winder arbor, or with a insertion in a ring operation; and
forming coils in the shape of a treble clef to form a mainspring prior to its first winding, or winding to form a balance spring, or insertion in a ring and heat treatment to form a mainspring.

14. The method for manufacturing a spiral spring according to claim 13 , wherein the last deformation phase is carried out in the form of flat unformed rolling, and wherein the last heat treatment is performed on the calendered or inserted in a ring or wound spring.

15. The method for manufacturing a spiral spring according to claim 13 , wherein there is applied to said alloy pairs of deformation precipitation heat treatment sequences, including the application of deformations alternating with heat treatments until a two-phase microstructure is obtained comprising a solid solution of niobium with β-phase titanium and a solid solution of niobium with α-phase titanium, the α-phase titanium content being greater than 10% by volume, with an elastic limit higher than or equal to 2000 MPa, the treatment cycle including beta-quenching at a given diameter, such that the entire structure of the alloy is beta, then a series of said pairs of deformation/precipitation heat treatment sequences, wherein each deformation is performed with a given deformation rate comprised between 1 and 5, the overall accumulation of deformations over the entire series of phases giving a total deformation rate comprised between 1 and 14, and which includes each time a precipitation heat treatment of the alpha phase Ti.

16. The method for manufacturing a spiral spring according to claim 15 , wherein said beta-quenching is a solution treatment, with a duration comprised between 5 minutes and 2 hours at a temperature comprised between 700° C. and 1000° C., under vacuum, followed by gas cooling.

17. The method for manufacturing a spiral spring according to claim 16 , wherein said beta-quenching is a solution treatment, with 1 hour at 800° C., under vacuum, followed by gas cooling.

18. The method for manufacturing a spiral spring according to claim 13 , wherein each pair of deformation/precipitation heat treatment sequences includes a precipitation treatment with a duration comprised between 1 hour and 80 hours at a temperature comprised between 350° C. and 700° C.

19. The method for manufacturing a spiral spring according to claim 18 , wherein each pair of deformation/precipitation heat treatment sequences includes a precipitation treatment with a duration comprised between 1 hour and 10 hours at a temperature comprised between 380° C. and 650° C.

20. The method for manufacturing a spiral spring according to claim 19 , wherein each pair of deformation/precipitation heat treatment sequences includes a precipitation treatment with a duration of between 1 hour and 12 hours at 450° C.

21. The method for manufacturing a spiral spring according to claim 13 , wherein said method includes between one and five of said pairs of deformation/precipitation heat treatment sequences.

22. The method for manufacturing a spiral spring according to claim 13 , wherein said first pair of deformation/precipitation heat treatment sequences includes a first deformation with an at least 30% reduction in cross-section.

23. The method for manufacturing a spiral spring according to claim 22 , wherein each said pair of deformation/p

Assignees

• Nivarox Sa

Inventors

• Charbon Christian

Classifications

• G04B17/06

  Oscillators with hairsprings, e.g. balance {(electrically driven balances G04C3/04; contacts actuated by a balance G04C13/065)} · CPC title

• C22C27/02

  Alloys based on vanadium, niobium, or tantalum · CPC title

• C22C14/00

  Alloys based on titanium · CPC title

• C21D1/18 Primary

  Hardening (C21D1/02 takes precedence); Quenching with or without subsequent tempering (quenching devices C21D1/62) · CPC title

• G04B1/145

  Composition and manufacture of the springs (compositions and manufacture of components, wheels, spindles, pivots, or the like G04B13/02; compositions of component escapements G04B15/14; composition and manufacture or hairsprings G04B17/066; compensation for the effects of variations of temperature of springs using alloys, especially for hairsprings G04B17/227; materials for bearings of clockworks G04B31/00; heat treatment and chemical or mechanical treatment for control of the structure C21D8/00; iron and steel alloys C22C; non-ferrous alloys C22C and B22F) · CPC title